House Extensions Wembley

GS Renovation plans and builds extensions across Wembley, on the interwar semis and terraced houses found among HA9's flats. We take on rear kitchen extensions, side and wrap-around projects, using the generous plots these suburban houses enjoy to add genuine, well-built living space rather than a cramped box on the back.

In Wembley, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Wembley: the structural engineer we appoint designs the structure, we build it, and building control signs it off.

Rear and side extensions on Wembley plots

The wide plots and side passages of Wembley's interwar semis lend themselves to side and wrap-around extensions that many tighter London terraces cannot manage. The most common HA9 project is a kitchen extension that goes into the side alley and out to the rear, creating an open-plan kitchen-diner that opens onto the back garden. We dig and pour the foundations to the depth building control requires, allowing for any nearby trees on these leafier suburban plots, then build up in matching brick or render.

Steel beams carry the old rear wall once the opening is formed, and we tie the new roof, whether a flat roof with lantern or a pitched addition, into the existing 1930s structure. Because these are semi-detached pairs, a party wall notice to the adjoining owner, served by you as building owner, is usually part of the process, and we supply the drawings it needs. We manage the groundworks, the steel, the roof and the weathertight shell as a continuous sequence.

Housing in Wembley

The Council Tax list puts Wembley at about 17,140 homes, 71% flats against 29% houses; 12% went up before 1919, 25% between the wars and 63% after 1945. Since most homes here are flats, a flat in Wembley has no householder permitted development rights, so extending one needs planning permission and the freeholder's consent.

Brent's extension depths applied to Wembley semis and terraces

Brent's Residential Extensions and Alterations SPD allows single storey rear extensions to attached homes of up to 6 metres from the original rear wall. The same SPD says two storey rear extensions to attached homes must not be more than 3 metres deep from the original rear wall. In Wembley that applies to the semis and terraces, and the word that catches people out is original. An interwar house with a later back addition or an earlier small extension is measured from where it first ended. These are the depths Brent applies to a planning application; permitted development has its own limits. Find the original line in the planning history before the extension is drawn.

Building control then depends on what is under the garden. Brent requires a full plans application for extensions built over, or within, three metres of a public sewer, and Brent Building Control otherwise takes either a full plans application or, in certain circumstances, a building notice. On Wembley's semis, a shared drain can run along the back of several gardens, so have it traced before choosing a route. Size matters to the fee too: Brent's charges guide has one item for a domestic single storey extension under 40m2, so ask how a larger wrap-around design is charged.

Planning and building control in Brent

Whether your Wembley extension is permitted development or needs a full planning application depends on the property and how far you go. Many single-storey rear extensions on these interwar plots fall under permitted development, up to 3 metres deep on a semi or 4 on a detached house, or 6 and 8 metres through the prior approval route, but double-storey work, anything close to a boundary, or a home already extended will often need permission from Brent Council. We assess your specific house honestly and, where required, coordinate the planning application with your architect or technician rather than leaving you to guess.

Every extension, whatever its planning route, must meet building regulations. Brent building control inspects the foundations, the damp proofing, the steelwork, insulation and drainage at set stages. We book these inspections and keep the paperwork straight so your completion certificate arrives cleanly. From first sketch to the final fit-out of kitchen, bathroom, plastering and decoration, one team runs the whole job across HA9.

Kitchen extensions in Wembley

71% of homes in Wembley are flats, and a flat has no householder permitted development, so a ground-floor flat's kitchen extension needs planning permission from Brent Council and the freeholder's consent. Most kitchen extensions here are on the 29% of homes that are houses. The fit-out is priced on its own page, kitchen renovation in Wembley; the build figures are in the table above.

Side return extensions in Wembley

71% of homes in Wembley are flats, so a side return here may belong to a ground-floor flat, which has no householder permitted development and needs planning permission from Brent Council and the freeholder's consent. On the 29% of homes that are houses, a side extension is limited to one storey, 4 metres high and half the house's width, and is not permitted development in a conservation area. Our side return extension page covers the build in detail, with build rates of £2,400 to £3,200 per m².

Double storey extensions in Wembley

Under permitted development a two-storey rear extension can go no more than 3 metres beyond the original rear wall and must stay at least 7 metres from the rear boundary, and in a conservation area it is not permitted development at all. Many gardens are too short for the 7 metre rule, so a double storey extension in Wembley often needs planning permission from Brent Council. It is a job for the 29% of homes that are houses; a flat cannot add a storey this way. Brent's Wembley High Street Conservation Area was designated on 19 March 1990 and has an article 4 direction (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.

• Side-return and rear extensions
• Insulation, airtightness and thermal detailing to regulations
• Party wall process explained, and the extension built to the award

VOA Council Tax stock of properties, March 2025, for Wembley North, Wembley West, Wembley East and Wembley Park. Counts rounded by the VOA.

Alongside house extensions in Wembley, the pages that usually help next are RSJ and steel beam installation in Wembley, house extensions across Brent, wraparound extensions, a garage conversion instead, house extensions across London and Crittall Doors Guide.

The GS Renovation Difference in Wembley

Homeowners in Wembley choose GS Renovation because we know how to use the generous interwar plot without falling foul of Brent Council or the party wall rules that come with semi-detached houses. With our founder's 30+ years on the tools, we handle foundations, steel, roof and fit-out under one roof, and we tell you straight whether you need planning permission.

• Garden levels and access made good where the build meets outside
• Clean, tidy and reliable tradespeople
• Insulation and thermal detailing to current regulations

Reviewed jobs near Wembley

1 MyBuilder review from Wembley, with each customer's own job title:

• Install new worktop, Wembley, 10 Jul 2024 (5 out of 5)

Read all 31 on our reviews page.

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.